Portable electronic devices (such as a cellular phone, a PHS, a personal digital assistant, a portable computer (mobile computer), and a digital camera), each of which include an optical zoom function together with an electronic camera and which can change a photographing field angle, have begun to spread. By the electronic camera described above, animations are frequently taken besides still pictures. In the portable electronic device as described above, as means for changing a photographing field angle, in particular, an actuator for moving a camera module, such as a lens, is mounted.
In Patent Literature 1, as the actuator described above, an actuator has been disclosed which has, between two housings, a motor having a rotor, two torque increasing gears for increasing a rotary torque generated from the motor, and an output gear which is engaged with one of the above gears and which outputs a power to drive a driven mechanism.